Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

Readings on 22 Nov 2014

View reading for:

Region

24-hr Sulphur dioxide(µg/m3)

24-hr PM10(µg/m3)

1-hr Nitrogen dioxide(µg/m3)a

8-hr Ozone(µg/m3)

8-hr Carbon monoxide(mg/m3)

24-hr PM2.5(µg/m3)

North

2(2)

28(28)

55(-)

15(6)

0.4(4)

17(56)

South

8(5)

20(20)

37(-)

15(7)

0.4(4)

11(45)

East

3(2)

16(16)

18(-)

28(12)

0.3(3)

11(44)

West

5(3)

31(31)

53(-)

24(10)

0.5(5)

17(57)

Central

9(6)

19(19)

32(-)

34(14)

0.5(5)

10(44)

1-hr PM2.5 (µg/m3)b Readings on 22 Nov 2014

View reading for:

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

North

26

37

22

20

20

22

18

16

18

9

10

10

South

3

11

2

8

14

20

13

4

14

11

20

27

East

6

3

6

11

11

19

24

23

14

16

8

10

West

20

9

18

18

22

20

18

17

20

16

25

19

Central

6

6

7

8

13

16

11

11

15

14

17

14

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

North

8

9

19

6

14

26

24

15

16

10

8

-

South

19

26

9

6

21

5

4

5

6

4

3

-

East

8

14

3

10

10

11

11

11

6

8

5

-

West

15

23

23

10

8

8

16

18

20

17

16

-

Central

6

25

10

5

17

6

13

9

6

6

4

-

Note:a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on
22 Nov 2014

Time

1am

2am

3am

4am

5am

6am

7am

8am

9am

10am

11am

12pm

3-hr PSI

46

48

51

51

52

56

57

56

55

54

55

54

Time

1pm

2pm

3pm

4pm

5pm

6pm

7pm

8pm

9pm

10pm

11pm

12am

3-hr PSI

54

55

54

52

47

45

52

50

49

43

38

-

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.